how to get the rpm and timing right without accelerating the engine too much?? on 1990 Mazda B2200

put a ground wire from the green test connector.Set the rpm to 750 on idle and timing on 6. As soon I disconnect the ground wire,the engine accelerate and rpm goes over 800.The repair manual ask me to ground the test connector so i did.Just want to have my rpms right to smog check. Thanks.

by in Sun Valley, CA on August 17, 2012
1 answer 2 comments
ANSWER by , August 19, 2012
Are you setting the idle speed with the ground connected or just the 'base' timing?
COMMENT by , August 19, 2012
Im setting idle speed and making sure timing is correct.Thats what the underhood label says: idle speed 750rpm and timing on 6 degrees. Just dont understand what is that ground wire connector for ? why do i need to ground it ??
COMMENT by , August 19, 2012
That is for setting the 'base' ignition timing only. Disconnect , then adjust idle. What else was done , leading to the need to make adjustments?